Fluid cushion cells for fluid cushion vehicles

ABSTRACT

According to the present disclosure, a deformable chamber is provided beneath the rigid body of a fluid cushion vehicle. A plurality of expansible chambers are mounted to the deformable chamber and in fluid communication therewith. Orifice means provides fluid communication between each expansible chamber and a region below it to form a fluid cushion cell. According to one feature of the present disclosure, the deformable chamber is confined to a region below the periphery of the body so as to define another cushion cell within its bounds.

United States Patent Eggington 51 Oct. 24, 1972 [54] FLUID CUSHION CELLSFOR FLUID 3,333,650 8/ 1967 Hardy et a1. ..180/128 CUSHION VEHICLES3,371,737 3/1968 Hall "180/121 X ,4 4 th' [721 New: f Eggmgmn Gammon,2433 336 311323 3216123321.. 123115; Cahf' 3,524,517 8/1970 La Fleur..180/ 124 [73] Assignee: Aerojet-General Corporation, El

Monte, Calif. Primary Examiner-Kenneth H. Betts [22] Filed: Aug. 30,1971 AttorneyEdward O. Ansell and D. Gordon Angus [21] Appl. No.:176,212 [57] ABSTRACT Related US. Application Data According to thepresent disclosure, :1 deformable chamber is provided beneath the rigidbody of a fluid [63] ggg g z 2 cushion vehicle. A plurality ofexpansible chambers a an one are mounted to the deformable chamber andin fluid communication therewith. Orifice means provides ((51..180/12861 fluid communication between each expansible chamber and aregion below it to form a fluid cushion [58] Fleld of Search "180/118119 cell. According to one feature of the present disclosure, thedeformable chamber is confined to a region [56] References C'ted belowthe periphery of the body so as to define UNITED STATES PATENTS anothercushion cell within its bounds.

3,267,882 8/ 1966 Rapson et a1. ..180/124 X 6 Claims, 2 Drawing Figures/2 3 J 7 /z/ /a is a /9 l8 A9 T 2 es Z5 described apparatus forstabilizing the body of a fluid cushion vehicle to prevent minorfluctuations while traveling over a rough or irregular terrain.Stabilization of the vehicle is effectuated by a valving mechanism whichautomatically increases and decreases the volume of fluid supplied to afluid cushion cell so that appropriate fluid rates are maintained whilethe vehicle experiences depressions and rises in the surface elevationof the terrain. Particularly, an expansible chamber is provided so thatif the pressure below the cushion cell decreases, as may be occasionedby a decrease in the elevation of the adjacent terrain surface, thepressure in the cushion cell decreases and the pressure differentialbetween the expansible chamber and the cushion cell increases so thatthe volumetric size of the expansible chamber increases so as to lowerthe bottom of the expansible chamber relative to the vehicle.Furthermore, fluid is passed into the cushion cell from the expansiblechamber.

It is an object of the present invention to provide a chamber disposedabout the periphery of a fluid cushion vehicle to form a cushion cellbeneath said vehicle.

It is another object of the present invention to provide a deformablechamber which supports individual expansible chambers and which forms acushion cell beneath the vehicle. The expansible chambers are capable ofadjusting in elevation in accordance with elevation changes of theadjacent terrain to react against the deformable chamber to shift thecenter of gravity of the vehicle.

In accordance with the present invention, a deformable chamber ismounted beneath the body of a fluid cushion vehicle. A plurality ofexpansible chambers are mounted to the deformable chamber and in fluidcommunication therewith. Means is provided in the expansible chambers toform individual cushion cells beneath each expansible chamber.

According to an optional and desirable feature of the present invention,the deformable chamber is mounted at the periphery of the vehicle andfluid under pressure in the fluid cushion cells formed beneath theexpansible chambers escapes into the region bounded by the deformableand expansible chambers to pressurize that region. The pressurized fluidin the region bounded by the chambers reacts against the surface of theterrain and against the vehicle to aid in the lifting of the vehicle.

According to another feature of the present invention, undulation of theterrain beneath the vehicle operates on respective expansible chamberswhich in turn operate on the deformable chamber to shift the center ofgravity of the deformable chamber. The shifted center of gravity of thedeformable chamber aids in stabilizing the vehicle.

The above and other features of this invention will be more fullyunderstood from the following detailed description and the accompanyingdrawings, in which:

FIG. 1 is a sideview elevation, partly in cutaway cross-section, of aportion of a fluid cushion vehicle having chambers which when inflatedform cushion cells in accordance with the presently preferred embodimentof the present invention; and

FIG. 2 is a bottom view of the vehicle illustrated in FIG. 1 taken atline 2-2 in FIG. 1.

In the drawings there is illustrated a fluid cushion vehicle having arigid housing or frame 10 defining an undercarriage 11. Membrane 12which may, for example, be constructed of sealed fabric such asneoprenecoated dacron or neoprene-coated nylon having a thicknessbetween about 0.005 and 0.015 inch, is mounted to housing 10 at theperiphery thereof to form a substantially enclosed deformable chamber17. Membranes 18 are mounted beneath deformable chamber 17 to formexpansible chambers 19. Preferably, chambers 19 are substantiallybellowed shape as illustrated in the drawings so that they may expandand contract in volume. Chambers 19 are in fluid communication throughorifice 20 with deformable chamber 17. Bias means 21 is mounted to thecenter of membrane 18 at its lowestmost portion and supports membrane 18by attachment to point 15 on frame 10. Bias means 21, may be a suitableelastic band or spring. The cell chamber 19 in vertical cross sectionwhen inflated may conform to a cloverleaf configuration. This is clearlyshown in FIG. 1, the shape being imparted by the attachment of therestraint by bias means 21 and the horizontal cross-ties 30 between theinside and outside walls of chamber 19. Orifice 22 are provided throughthe lowermost portion of membrane 18 to provide fluid communicationbetween chambers 19 and regions 27 between membranes 18 and surface 28of the terrain. Although FIG. 2 illustrates a single row of orifices 22in the lowermost portion of each expansible chamber, it is to beunderstood that the orifices 22 preferably form a curtain of air jetsaround each region 27 and therefore several rows of orifices or a singlecircular slot around the region may be desirable for particularapplications.

Deformable chamber 17 and the individual expansible chambers 19 togetherform a cushion cell 23 beneath the vehicle. As illustrated in thedrawings, cushion cell 23 is bounded by chambers 17 and 19. If desired,additional orifices 13 may be provided in membrane 12 to provide fluidcommunication between deformable chambers 17 and cell 23.

In operation of the apparatus illustrated FIGS. 1 'and 2, fluid underpressure is admitted through inlet openings 24 in housing 10 intochambers 17. The fluid passes through orifices 20 into expansiblechambers 19 formed by membranes 18. The fluid displaces membranes 12 and18 so as to inflate the chambers to a size dependent upon the size ofthe respective membranes and the bias force provided by bias means 21.Pressurized fluid in chambers 19 passes through orifices 22 to form anair cushion in region 27 below chamber 19. Pressurized air beneathchambers 19 escapes in the direction of arrows 25 and 26 to the regionon each side of the chamber.

Air escaping from region 27 in the direction of arrow 26 escapes intochamber 23 to maintain the pressure in that chamber. The bulging shapeof the chambers 17 at the periphery is thus maintained by pressurewithin chambers 17 and 23. Pressurized fluid in region 27 beneath theindividual chambers 19 as well as the pressurized fluid in chamber 23reacts against the surface 28 of the terrain to thereby lift againstmembrane 18 and surface 11 of the vehicle. The pressure against thebottom of membranes 12 also reacts against the bottom of the vehicle.Pressure against the bottom of the vehicle lifts the vehicle from thesurface 28 of the terrain. If desired, orifices 13 may provide directfluid communication between chambers 17 and cell 23.

If the vehicle moves in the direction from right to left in FIG. 1 sothat the surface below the vehicle decreases in altitude, the pressurewithin region 27 below chamber 19 decreases due to the loss ofpressurized fluid escaping through the enlarged distance betweenmembranes 18 and surface 28 of the terrain. The decreased pressurewithin region 27 alters the pressure differential between region 27 andin chamber 19 so that chamber 19 expands downwardly until thepressurized fluid within chamber 19 is balanced by the elastic forceprovided by bias means 21, the pressure within region 27 and the tensionin membrane 18. Furthermore, the pressure within chamber 19 decreasesthereby altering the pressure differential between chambers 19 and theadjacent portion of chamber 17. The altered pressure differentialbetween chambers 17 and 19 alters the force on chamber 17 so thatchamber 17 deforms downwardly and inwardly. Since the position ofchamber 17 is shifted, the center of gravity of the vehicle also shifts.Specifically, when the pressure in region 27 decreases, chamber 19expands and decreases in pressure. The decreased pressure in chamber 19permits chamber 17 to push downwardly on chamber 19 and to compressinwardly due to the pressure in chamber 23 and of the atmosphere. Theshift continues until the forces are again balanced, and results in ashift in the center of gravity of chamber 17.

If the vehicle moves from left to right in FIG. 1 so that the surface ofthe terrain is increasing in altitude, the pressure within the region 27below chamber 19 increases due to the decreased space between chamber 19and surface 28 of the terrain. The increased pressure within region 27reacts against chamber 19 to raise membrane 18 to decrease the size ofchamber 19. Chamber 19 decreases in size until a balance is reachedbetween the fluid pressurizing chamber 19 and the force of thepressurized fluid in region 27, bias means 21 and the tension inmembrane 18. Likewise, due to the increased pressure in chamber 19, thepressure differential between chamber 19 and the adjacent portion ofchamber 17 is altered to alter the forces on chamber 17 to thereby shiftits center of gravity. Hence, chambers l7 and 19 react to closely followthe terrain of surface 28. Thus, the cushion cells automatically adjustto fluctuations in the elevation of the terrain.

One feature of this invention resides in thefact that when the pressurewithin region 27 increases'due to a rise in elevation of the adjacentterrain thereby decreasing the size of chambers 17 and 19, less fluid ispassed through the orifice due to the increased pressure in region 27.Likewise, when the elevation of the terrain decreases, more fluid ispassed through orifices 22 to region 27 below cushion 19 due to thedecreased pressure in the region 27. Hence, the volume of fluid passedby orifices 22 is self-regulating in accordance with changes of theelevation of the terrain. Furthermore, the pressure within chamber 23 isrelatively insensitive to changes in elevation of the terrain.

Reaction of the individual expansible chambers 19 against chambers 17causes alteration of the center of gravity of the chamber and aids inthe stabilization of the vehicle when traversing an irregular orundulating surface.

The present invention thus provides cushion cells which are capable ofadjusting in elevation and in center of gravity in accordance withfluctuations in the elevation of the surface terrain. The cells providemobility over irregular and uneven surfaces such as bodies of waterrough ground. The cells are easily fabricated and effective in use.

This invention is not to be limited by the embodiment shown in thedrawings and described in the description, which is given by way ofexample and not of limitation, but only in accordance with the scope ofthe appended claims.

We claim:

1. In a fluid cushion vehicle having a rigid body, a cushion cellcomprising: first membrane means mounted to and depending from said bodydefining a deformable chamber and forming with said body a compartmentfor retaining a cushion of pressurized fluid therein as a support forthe vehicle above a surface; aninlet opening into said deformablechamber adapted to supply said deformable chamber with pressurizedfluid; second membrane means mounted to and depending from said firstmembrane means defining a plurality of individual expansible chambers,each chamber of said plurality being individually mounted to said firstmembrane means and in lateral touching relationship with the adjacentchamber of said plurality, said first membrane means and said secondmembrane means defining said compartment, each chamber capable ofexpansion and contraction in a vertical direction independently of anyother chamber in said plurality; a plurality of first orifice meansproviding fluid communication between said deformable chamber and eachof said expansible chambers; and outlet means providing fluidcommunication between each of said expansible chambers and a regionbelow each of said expansible chambers whereby fluid under pressure ispassed from each of said expansible chambers to said region.

2. Apparatus according to claim 1 further including bias meanssupporting said second membrane means, said bias means providing for theexpansion or contraction of each of said expansible chambers in avertical direction independently, in dependent upon the fluid pressurein each said chamber.

3. Apparatus according to claim 2 further including means confining saidexpansible chamber in a lateral direction relative to said lateraltouching relationship.

4. The system of claim 3 wherein each said expansible chamber, invertical section, conforms, when provided with pressurized fluid, tocloverleaf configuration.

5. A system according to claim 1, further including second orifice meansin said first membrane means providing fluid communication between saiddeformable chamber and said compartment.

6. Apparatus according to claim 1 wherein said outlet means providingfluid communication between each of said expansible chambers and theregion beneath them comprise means for providing a curtain of air jetsaround the bottom periphery of said expansible cham- 5 hers.

1. In a fluid cushion vehicle having a rigid body, a cushion cellcomprising: first membrane means mounted to and depending from said bodydefining a deformable chamber and forming with said body a compartmentfor retaining a cushion of pressurized fluid therein as a support forthe vehicle above a surface; an inlet opening into said deformablechamber adapted to supply said deformable chamber with pressurizedfluid; second membrane means mounted to and depending from said firstmembrane means defining a plurality of individual expansible chambers,each chamber of said plurality being individually mounted to said firstmembrane means and in lateral touching relationship with the adjacentchamber of said plurality, said first membrane means and said secondmembrane means defining said compartment, each chamber capable ofexpansion and contraction in a vertical direction independently of anyother chamber in said plurality; a plurality of first orifice meansproviding fluid communication between said deformable chamber and eachof said expansible chambers; and outlet means providing fluidcommunication between each of said expansible chambers and a regionbelow each of said expansible chambers whereby fluid under pressure ispassed from each of said expansible chambers to said region. 2.Apparatus according to claim 1 further including bias means supportingsaid second membrane means, said bias means providing for the expansionor contraction of each of said expansible chambers in a verticaldirection independently, in dependent upon the fluid pressure in eachsaid chamber.
 3. Apparatus according to claim 2 further including meansconfining said expansible chamber in a lateral direction relative tosaid lateral touching relationship.
 4. The system of claim 3 whereineach said expansible chamber, in vertical section, conforms, whenprovided with pressurized fluid, to cloverleaf configuration.
 5. Asystem according to claim 1, further including second orifice means insaid first membrane means providing fluid communication between saiddeformable chamber and said compartment.
 6. Apparatus according to claim1 wherein said outlet means providing fluid communication between eachof said expansible chambers and the region beneath them comprise meansfor providing a curtain of air jets around the bottom periphery of saidexpansible chambers.